"Only if we work together, through sharing of information, by pooling our resources, will we ultimately be able to defeat those who are in a struggle with us about our fundamental values," said Holder.

The meeting, which was also attended by the EU’s counter-terrorism coordinator and the EU commissioner for home affairs, laid out a list of policy priorities to tackle what is seen as the growing threat of foreign fighters returning home.

The fear is that the some 2,500 EU nationals that have gone to Syria and Iraq to fight along Islamic militants may come back to the EU even more radicalised.

The Jewish museum shootings in Brussels last year and now the Paris attack have led to intensified calls to shore up security at the EU’s external borders, increase Internet surveillance measures, and pass new laws that could criminalise foreign fighters.

Latvia, holding the EU presidency, has called for an EU-wide ministerial meeting of home affairs this week in Brussels to discuss new counter-terrorism measures.

"The fight against all forms of expression of terrorism is high on my agenda and Latvia as the current Presidency of the Council of the EU will definitely draw specific attention to this issue,” said Latvia's interior minister Rihards Kozlovskis.

This includes making travelling for terrorism or related training a serious criminal offence.

The idea stems from the legally binding UN security council resolution 2178, adopted last September, which calls upon national governments to insert the offence into their legal systems.

EU home affairs ministers backed it in October and then again in December after Gilles de Kerchove, the EU's counter-terrorism coordinator, proposed revising the so-called EU 2002 framework decision on combating terrorism.

France inserted the new rules into national law in November. They impose sentences of up to ten years and fines of up to €150,000 on “anyone found to be simultaneously in possession of dangerous objects or substances (such as explosives and weapons), and consulting terrorist websites or receiving terrorist training.”

According to transparency NGO La Quadrature du Net, the French government, in the immediate aftermath of the Paris attack, passed further decrees that allows authorities to shut down, without getting a court order, websites advocating or provoking terrorism.

Other member states are also in the process of following the UN resolution demands, Spain's interior minister Jorge Fernandez Diaz told the El Pais newspaper on Sunday.

Giovanni Buttarelli, the European data protection supervisor, says the EU-US data sharing pact known as Privacy Shield will play an increasingly minor role given the general data protection regulation.

The Kingdom of Bahrain has refused to host a visit by MEPs from the parliament's official human rights committee, citing scheduling conflicts - while helping organise one from an unofficial 'friendship group'.